Also published, 1st edition, London: Figurehead, November 1933; 4th revised edition, London: Figurehead, November 1935; 5th edition, Bullsbrook, Western Australia: Veritas, 1983. Colbourne developed an earlier work of his, <i>Unemployment or war </i>(New York: Coward-McCann, 1928), which includes discussion of Douglas' economic theory, into <i>Economic nationalism </i>(London: Figurehead, 1933, 2nd edition, London: Figurehead, 1934); which he revised to become, 4th revised edition, <i>The meaning of Social Credit </i>. John A. Irving, in <i>The Social Credit movement in Alberta </i>, says it was <i>Unemployment or war </i>, along with pressure from an acquaintance, Charles M. Scarborough, which convinced Aberhart that Social Credit was the solution to unemployment, while he was still a teacher. Among Colbourne's other works on economics is, <i>The sanity of Social Credit </i>, 1st printing, London: Stanley Nott, June 1935, 2nd printing October 1935; and Toronto: W. Dawson Subscription Service, [1935]. Most of this work was first delivered as a lecture to the London Social Credit Club in 1935.